1. Field of the Invention
The present invention relates to an image processing apparatus that detects marks (entry) on a read mark-sensing sheet filled in by a user to determine content instructed by the user according to the detected result. In particular, the image processing apparatus detects corrections of marks made by the user based on the contents of the read mark-sensing sheet.
2. Description of the Related Art
An image processing apparatus may include a function in which a user provides the image processing apparatus with instructions using a mark-sensing sheet in which a plurality of mark (entry) fields are printed for each selected item. A user fills in or darkens a mark (entry) field according to a selection by the user using a pencil, a pen, or the like among a plurality of mark fields printed on a mark-sensing sheet, and the image processing apparatus optically reads the mark-sensing sheet. The image processing apparatus recognizes content selected by the user after optically reading the mark-sensing sheet.
The user may find a mark mistake on the mark-sensing sheet after the image processing apparatus has read the content entered on the mark-sensing sheet. The user may want to erase a field where a mark mistake is found to correct the field on the mark-sensing sheet. Alternatively, the user may also reprint the mark-sensing sheet and mark it again rather than erase the field where the mark mistake was found.
When the user erases the field where the user marked the mark-sensing sheet or reprints the mark-sensing sheet, it may take a long time for the corrected mark-sensing sheet to be read again. Further, resources such as an eraser, correction fluid, ink for reprinting, and paper are used.
A method for avoiding the use of additional resources and reducing the time needed for correcting the mark-sensing sheet is described in Japanese Patent Application Laid-Open No. 2-8978. Japanese Patent Application Laid-Open No. 2-8978 discusses a mark field for invalidating the marked field on the mark-sensing sheet. When the mark-sensing sheet is read, if the mark field for invalidating the marked field is filled in, the mark in the marked field on the mark-sensing sheet is invalid.
To address the user's need to change the mark field to be marked and not merely canceling the marked field, in Japanese Patent Application Laid-Open No. 2-120996, a technique is discussed where a user marks a mark field for revision provided for each selection item. If a user has filled in the wrong field different from the intended selection item, the user may correct the error using the mark field for revision.
However, in the above-described technique, the quantity of revision fields that are required is equivalent to the quantity of selection items on the mark-sensing sheet and redundant mark fields must be added on the mark-sensing sheet having limited area. The size of the mark-sensing sheet may increase due to the added mark fields. This may also increase the number of mark-sensing sheets required. Furthermore, an increase in the number of mark fields may increase the time required to detect marks in a mark field after reading.
In Japanese Patent Application Laid-Open No. 2002-55921, a technique is discussed where a plurality of mark fields has been filled in for a selected item. The newer content is used for updating information to the image processing apparatus.
However, this technique may limit the selection items to those selections that can be estimated as newer content. Unfortunately, which selection is newer may not always be determined. Thus, a change not considered an update (e.g., a change from “occupied” to “unoccupied”), makes revision more difficult.